The invention relates to a manipulator having an object holder. The object holder is displaceable with respect to a fixed frame in three substantially orthogonal directions of translation and at least one direction of rotation. The object holder is connected through identical first and second coupling members to first and second identical driving members for moving the object holder in the first and second directions of translation. The coupling members are wires, and the driving members are secured to the frame. The object holder is also connected by a third coupling member to a third driving member. The third coupling member is also a wire, and the third driving member is also secured to the frame. The third coupling member and the third driving move the object holder in the third direction of translation. Finally, the object holder is connected through a fourth coupling member to a fourth driving member. The fourth driving member rotates the object holder in a first direction of rotation, and is secured to the frame.
In the known manipulator described above (see, British Pat. No. 1,146,472), the object holder (a table) can be translated in three substantially orthogonal coordinate directions and can be rotated about an axis which is perpendicular to the plane of the table. One of the translations is in a direction perpendicular to the plane of the table by a coupling member and a driving member whose constructions differ essentially from the constructions of the coupling members and driving members for the remaining two directions of translation.
A disadvantage of the known manipulator is that a comparatively large number of different components are required to make the coupling members and driving members for the different directions of translations. Moreover, the number of degrees of freedom of the known manipulator is limited to four. As a result, the table can rotate about only one axis of rotation.